Lamp, tube, and similar devices



Jan. 28, 1936. R, B, THOMAS 2,028,884

LAMP, TUBE AND SIMILAR DEVICES Filed June 21, 1934 2 Sheets-Sheet l L 1' 7 INVEINTOR BY fw fl ATTORNEY Jan. 28, 1

- H R. B. THOMAS 2,028,884

LAMP, TUBE AND SIMILAR DEVICES Filed June 21, 1934 2 Sheets-Sheet 2 INVENTOR T'j- BY ATTO R N EY ?atented Jan. 2%, i936 almanac 1. TUBE, AND s pnvrcrzs Ralph E. Thomas, Salem, Mass, assignor to Hygrade Sylvania Corporation, Salem, Mesa, a corporation of Massachusetts Application June 21, 1934, Serial No. 231,581

7 Claims.

This invention relates to lamps, tubes and similar devices, and more particularly to improvements in methods and means for basing such devices.

An object of the invention is to provide an improved form of cementless based lamp or tube.

Another object is to provide an improved manner of mechanically bonding a contact base to a vitreous body such as a lamp bulb'or the like.

A feature of the invention relates to a cementless based lamp or tube, wherein means are provided to increase the resistance to relative tuming between the lamp bulb and the base.

Another feature relates to improved means for interlocking a contact base with a lamp bulb or the like.

Another feature relates to a cementless based lamp or tube having means for equally distributlng torsional strains around the periphery of the ggliigdcfillg areas between the base and lamp A further feature relates to the novel organization, arrangement and relative location of parts which go to make up a cementless based lamp which is efficient in use and economical oi manufacture.

Other features and advantages not specifically enumerated will be apparent after a consideration of the following detailed descriptions and the appended claims.

While the invention will be disclosed herein as embodied in specific forms, it will be understood that this is done merely for purposes of illustration and not by way of limitation.

In the drawings, Fig. 1 is an exploded view of a portion of a bulb based according to the invention.

Fig. 2 is a top plan view of thebulb of Fig. 1 prior to application of the base thereto.

Fig. 3 is an assembled sectional view of Fig. 1

taken along the line 33 thereof.

Fig. 4 is an exploded view of a modified manner of basing a lamp or tube.

Fig. 5 is a top plan view of the lamp or tube of Fig. 4 prior to the assembly of the base thereon.

Fig. 6 is a sectional assembled view of the device illustrated, in Fig. 4.

Fig. 7 illustrates a modification of Fig. 6.

Fig. 8 illustrates a further modification of the invention.

Fig. 9 is a sectional view of the modification of Fig. 8 with the metallic base in assembled 55 position.

Fig. 10 is a sectional view of Fig. 9 taken along the line Ill-w thereof.

; Inasmuch as the invention is primarily concarried with methods and means for applying a contacting base to lamps, tubes or similar devices, only those portions of the device that are 5 necessary to an understanding of the invention are shown, and the correspondin parts throughout the several figures of the drawings are designated by the same numerals.

Referring to Figs. 1 to 3, the numeral l indi- 1O cates the neck portion of a lamp, tube or similar device, the bulb portion oi which may be of any conventional or known shape. The neck portion 4 terminates in a butt portion 2 of uniformm diameter which is provided with a suitable threaded surface, preferably similar to the thread usually employed in ordinary incandescent lamp bases. While any well known method of threading may be employed, it is preferred 20 to form this thread by a molding operation. Preferably at the time the thread is molded into the butt portion 2, the necl: l is also formed with a uniform annular shoulder 3. Sealed to the portion 2 is a reentrant stem 3 which may terminate in a pram (not shown) wherein are sealed the various lead-in wires 5, ii. For the purpose of wvacuating the device and for communicating with the interior of the bulb, there is provided the usual exhaust tubulation l. By 30 means of this tubulation air under pressure may be forced into the bulb at the same time that the parts i and 2 are being heated to seal the stem to the bulb, and preferably a suitable mold is provided so that parts i and 2 when they 35 become molten are blown to provide the shoulder 3 and the threads in the portion 2. The mold is also designed to form the portion 2 with a plurality of rectangular depressions or grooves 8 which, however, extend only part way down the portion 2. While the drawings show the device formed with three equally spaced depressions or grooves, it will be understood that a greater or less number may be employed. Furthermore while the drawings show the grooves extending 45 substantially parallel to the axis of the device and of uniform depth, these grooves may be formed with tapered edges and if desired may be inclined inwardly toward the axis or the device. Adapted to fit over the end of the butt 50 portion 2 is a wire clip 9 which, in the particular embodiment disclosed, is substantially triangular and provided with downwardly depending arms i0 adapted to register with corresponding grooves 8. Preferably the clip 9 is made of a spring wire such as copper, brass, bronze or other metal which is easily soldered and if desired, a tinned coating may be applied to the arms Ill to facilitate soldering. Prior to positioning the clip in place the lead wire 5 is bent back on itself, as shown in the lower portion of Fig. l, and fits into one of the grooves 8 and preferably the lead wire 5 is of such a length that its free end does not protrude from the groove. Thus when the clip 9 is fastened in place, it contacts andretains the lead wire 5 in position. A quantity of solder is positioned in each of the grooves 8 and then the threaded metal base I l is screwed on to portion 2 until the lip l2 seats against shoulder 3.

The based end of the device is then heated to a. predetermined temperature to cause the solder the grooves to flow, thereby bonding clip 9 to the metal base ll. When the solder solidifies it is firmly bonded to the base I l and forrms a plurality of keys which are interlocked with the grooves 8, and these solder keys are also firmly bonded to the arms Not the wire clip. It will be understood or course that the solder may be fastened to the arms l0 prior to assembly of the clip in place, and a. quantity of suitable flux may be applied to these arms to ensure a proper soldered joint between the base, clip and lead wire. Preferably, although not necessarily, sufiicient solder is employed in each groove to substantially completely fill the groove, when the solder solidifies. It will be understoed of course that the other lead wire 6 is threaded through the insulated metal button I 3 and soldered thereto in any wellknown manner.

The embodiment of Figs. 1 to 3 therefore provides a rigid interlocking bond between the lamp or tube and its metallic base, and any strain resulting from the insertion or removal of the lamp into or out of its socket, is substantially equaliy distributed around-the base. Furthermore the utilization of the clip 9 enables the glass to be effectively bonded by the solder to the metal cf the base, thus eliminating the usual cements eni ployed for this purpose.

" in any well known manner but are preferably molded at the same' time that the threads are molded. The lead-in wire 5 is bent over the edge of the rim [4 preferably with its free end in one of the grooves I5, and then a ring 5 of solder is placed around the rim as shown. The metal shell base I i is then screwed into place until the lip i2 engages shouider 3, and the assembly is then heated so that the solder ring melts and flows into the grooves I5 and contacts with the thread of the metal base. when hardened, the solder is firmly bonded to the metal base and provides a plurality cf keys which are distributed uniformly around the periphery of the base. If desired, the inner surface of the metal base It may be previousiy tinned to facilitate bonding with the solder. Preferably the grooves l5 are formed and dispcsed on the uppermost thread so as to aliow the molten solder to flow easily into said grooves, but further downward flow of the molten solder is prevented by the thread of the metal base. It

will be understood of course that while the drawings show only the uppermost thread of the butt 2 provided with grooves, the remaining threads may likewise be grooved for the same purpose.

Instead of molding the threads of butt 2 with individual grooves as in Figs. 4, 5-and 6, the threads may he roughened or provided with a multiplicity of channels or furrows preferabiy, although not necessarily, extending parallel to the vertical axis of the device. Thus as shown in Fig. 7 the threads of the butt 2 are molded with a roughened or furrowed surface. This roughened surface may be obtained by employing a mold which has its surface for forming the threads, knurled, fine milled, sandblasted, 'pineh pricked etc., it being understood of course that if desired a smooth surface mold may be employed and the surface of the glass threads may be roughened subsequently by any'well known process. The manner of basing the device of Fig. 7 is substantially the same as that described for Figs. 4, 5 and 6, namely by employing a ring N5 of solder which is seated on the rim H prior to assembly of the metal shell base. Heat is then applied to melt the solder ring which flows downwardly to fill the furrows or pits on the threaded butt 2.

Referring to Figs. 9 and 10 there is shown a still further modification of the invention. In this embodiment the threaded butt 2 is provided, pref erably during the molding operation, with a series of equahy spaced depressions I! which may be spherical, or truncated conical shape. These depressions may be located along the pitch or contour of a thread as shown for example in Fig. 4, or they may be in the same plane or in any other location desired. A vertical groove I3 is also molded in the butt so that the lead-in wire 5 may be bent back on itself into said groove, and preferably the lead-in wire 5 is sufiicientlyiong to ailow a portion to protrude outside the metal base H when the latter is screwed in place. The emerging end of the lead-in wire is then soldered to the outside face of the metal bae, and the point of emergence may serve as an index for the operation about to be described. The based lamp is then screwed into an appropriate jig or holder which has a series of holes and an index bearing the samerelation to each other, as do the groove l8 and the depressions II. The based lamp having been inserted in the jig with the groove E8 or the soldered lead-in wire 5 in registry with the index on the lie. a specially shaped spinning tool is brought into engagement with the metal base causing the metal of the base in alignment with the depressions I'l te be spun into said depressions, as shown in Fig. 9. it will be understood of course that instead of employing a single spinning tool, a suitable head having a plurality of separate spinning tchlscorresponding in number and position to the depressions ll may be used to force simultaneously all the points on the metal shell base into said depressions.

"-Jarious changes and modifications mey be made herein without departing from the spirit and scope of the invention.

Thus while the invention has been disclosed in connection with a lamp bulb er similar device, it is capable of application to any device having a. threaded end of insulated material which is provided with a-metal cap or contact base, and accordingly the term vitreous is employed in the claims and is intended to cover notonly glass bodies but any other body of insulation material. Subject matter disclosed herein but not claimed this application is claimed in copending application Serial No. 758,349, filed December 20th, 1934.

What I claim is:-

1. In combination, a lamp or similar device having a screw-threaded base portion, a plurality of grooves distributed around the periphery of said base, a metal ring surrounding said base and having portions extending into said grooves, and a metal shell fitted over the said base, said ring being integrally bonded to said shell. I

2. In combination, a lamp or similar envelope having a threadedbase portion of insulating material, a metal clip fitted over the end of said base portion, means to prevent relative rotation between said clip and envelope, and a threaded metal shell fitted over said base portion and integrally bonded to said clip.

3. In combination, a lamp or similar device terminating in a threaded vitreous base portion, a metal clip mounted on said base portion and interlocked therewith, and a threaded metal shell base threaded on to said base portion, and integrally bonded to said clip.

4. In combination, a lamp or similar device having a screw-threaded base portion, a wire' clip interlocked with said base portion, and a screwthreaded metal shell threaded on to said base portion and integrally soldered to sfid clip.

5. In combination, a lamp or similar envelope terminating in a threaded end portion, a plurality of grooves in said threaded portion, a clip having projections fitted into said grooves, a screw-threaded metal shell base for said threaded end portion, and a quantity of bonding material in said grooves integrally bonding said projections to said shell.

6. In combination, a lamp or similar envelope terminating in a threaded base, a plurality of depressions in said base extending transversely of said threads, said grooves being spaced around -the periphery of said base, a metal member having a plurality of oflset portions seated in said depressions, and a metal shell fitted over said base and soldered to said offset portions.

7. In combination, a lamp or similar envelope terminating in a threaded base, a metal shell threaded on said base, and means to prevent relative turning between said base and shell comprising a plurality of grooves in one 01' the threads of said threaded base said grooves being spaced around the base, and metal means having a ring portion around said base and having projections extending into said grooves said metal means being integrally bonded to said shell.

RALPH B. THOMAS. 

